title: N-linked glycan profiling of mature human milk by high-performance microfluidic chip liquid chromatography time-of-flight tandem mass spectrometry.
abstract: N-Linked glycans of skim human milk proteins were determined for three mothers. N-Linked glycans are linked to immune defense, cell growth, and cell-cell adhesion, but their functions in human milk are undetermined. Protein-bound N-linked glycans were released with peptidyl N-glycosidase F (PNGase F), enriched by graphitized carbon chromatography, and analyzed with Chip-TOF MS. To be defined as N-glycans, compounds were required, in all three procedural replicates, to match, within 6 ppm, against a theoretical human N-glycan library and be at least 2-fold higher in abundance in PNGase F-treated than in control samples. Fifty-two N-linked glycan compositions were identified, and 24 were confirmed via tandem mass spectra analysis. Twenty-seven compositions have been found previously in human milk, and 25 are novel compositions. By abundance, 84% of N-glycans were fucosylated and 47% were sialylated. The majority (70%) of total N-glycan abundance was composed of N-glycans found in all three milk samples.
authors.affiliation: Department of Food Science, University of California at Davis, Davis, California 95616, United States.
authors.forename: David C
authors.initials: DC
authors.lastname: Dallas
authors.forename: William F
authors.initials: WF
authors.lastname: Martin
authors.forename: John S
authors.initials: JS
authors.lastname: Strum
authors.forename: Angela M
authors.initials: AM
authors.lastname: Zivkovic
authors.forename: Jennifer T
authors.initials: JT
authors.lastname: Smilowitz
authors.forename: Mark A
authors.initials: MA
authors.lastname: Underwood
authors.forename: Michael
authors.initials: M
authors.lastname: Affolter
authors.forename: Carlito B
authors.initials: CB
authors.lastname: Lebrilla
authors.forename: J Bruce
authors.initials: JB
authors.lastname: German
mesh_terms: D002851:Chromatography, High Pressure Liquid / Q000379:methods*; D006801:Humans; D013058:Mass Spectrometry / Q000379:methods*; D044085:Microfluidics / Q000379:methods*; D008895:Milk, Human / Q000737:chemistry*; D011134:Polysaccharides / Q000737:chemistry*
chemical_list: D011134:Polysaccharides